Simon, Count of Ponthieu
|Simon of Dammartin, Count of Ponthieu|
|Spouse(s)||Marie, Countess of Ponthieu|
|Noble family||House of Dammartin|
|Father||Alberic II of Dammartin|
|Mother||Mathildis of Clermont|
|Died||21 September 1239|
Simon of Dammartin (1180 – 21 September 1239) was a son of Alberic II of Dammartin (Aubry de Dammartin) and his wife Mathildis of Clermont.
Simon was the brother of Renaud I, Count of Dammartin, who had abducted the heiress of Boulogne, and forced her to marry him. It is thought that in order to strengthen the alliance with the Dammartins, King Philip Augustus of France allowed Simon to marry Marie, Countess of Ponthieu, who was a niece of the king, in 1208. Renaud and Simon of Dammartin would eventually ally themselves with John, King of England. In 1214 the brothers stood against Philip Augustus in the Battle of Bouvines. The French won the battle, and Renaud was imprisoned, while Simon was exiled.
Marie's father William IV, Count of Ponthieu had remained loyal to Philip Augustus. When William died in 1221, Philip Augustus denied Marie her inheritance and gave Ponthieu in custody to his cousin Robert III, Count of Dreux. After the death of Philip Augustus, Marie was able to negotiate an agreement with his successor Louis VIII in 1225. Ponthieu was held by the king, and Simon would only be allowed to enter this or any other fief if he obtained royal permission. In 1231 Simon agreed to the terms and added that he would not enter into marriage negotiations for his daughters without consent of the king.
- Joan, Countess of Ponthieu (1220–1278), married 1) Ferdinand III of Castile. Mother of Eleanor of Castile, the wife of Edward I of England. Married 2) Jean de Nesle, Seigneur de Falvy et de La Hérelle.
- Mathilda of Dammartin (-1279), married John of Châtellerault
- Philippe of Dammartin (-1280), married 1) Raoul II of Lusignan, 2) Raoul II, Lord of Coucy, 3) Otto II, Count of Guelders.
- Maria of Dammartin, married John II, Count of Roucy.
- John W. Baldwin, Aristocratic Life in Medieval France: The Romances of Jean Renart and Gerbert de Montreuil, 1190-1230, JHU Press, 2002
- Willelmi Chronica Andrensis 194, MGH SS XXIV, p. 755.
- Layettes du Trésor des Chartes II, 1713, p. 56.
- Nobility of Northern France from Medieval Lands